Hi Andy,
at first: Welcome to the "Club"!
I´m surprised that WDP 8.41 is running well on a 486-PC...The (very) minimum requirement is a Pentium 233MHz and if you have more than 5 locomotives I recommend to take a "More_Up_To_Date"-PC!
If you change the layout-size to 16x16, WDP should start with the same size next time you start WDP.
What´s the resolution of your PC-screen? 800x800 or 1.024x768? Is it impossible for you to change the layout-resolution or does it just switch back to 24x24 next time you start WDP?
Regarding your problem with the ICE3 (37780) is well known. This is due to settings of the IB. Please do the following:
1) Enter loc-address on the IB
2) Switch "Loc-menu"
3) Goto last entry of this menu (special settings)
4) configure Option-4 (left) to "0" (right).
5.) That´s it. Now it works with the IB AND WDP!
This is not a WDP / PC-problem, but more or less an IB / Decoder problem.
Regards
Rüdiger